Light-emitting diodes (LEDs) can be formed using a compound semiconductor material such as GaAs-based, AlGaAs-based, GaN-based, InGaN-based and InGaAlP-based materials.
Such a light-emitting diode is used as a light-emitting device that is packaged and emits various colors and the light-emitting device is used as a light source in various applications such as a light indicator to indicate color, a character indicator, and an image indicator.
In particular, ultraviolet ray emitting diodes (UV LEDs) can be used for sterilization, purification or the like in a case of a short wavelength, and can be used in a light-emitting apparatus or a curing apparatus in a case of a long wavelength. However, since an environment in which the ultraviolet ray emitting diode using the short wavelength is applied is often high humidity or underwater, the apparatus may be defective due to deterioration of a moisture-proof and waterproof function thereof and the operation reliability may be decreased.